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Hibernate example source code file (LockOptions.java)

This example Hibernate source code file (LockOptions.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Hibernate tags/keywords

hashmap, io, iterator, lockmode, lockmode, lockoptions, lockoptions, map, no_wait, none, none, serializable, upgrade, util, wait_forever, wait_forever

The Hibernate LockOptions.java source code

// $Id:$
/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
 * third-party contributors as indicated by either @author tags or express
 * copyright attribution statements applied by the authors.  All
 * third-party contributions are distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;


/**
 * Contains locking details (LockMode, Timeout and Scope).
 * 
 * @author Scott Marlow
 */
public class LockOptions implements Serializable {
	/**
	 * NONE represents LockMode.NONE (timeout + scope do not apply)
	 */
	public static final LockOptions NONE = new LockOptions(LockMode.NONE);
	/**
	 * READ represents LockMode.READ (timeout + scope do not apply)
	 */
	public static final LockOptions READ = new LockOptions(LockMode.READ);
	/**
	 * UPGRADE represents LockMode.UPGRADE (will wait forever for lock and
	 * scope of false meaning only entity is locked)
	 */
	public static final LockOptions UPGRADE = new LockOptions(LockMode.UPGRADE);

	public LockOptions() {
	}

	public LockOptions( LockMode lockMode) {
		this.lockMode = lockMode;
	}

	private LockMode lockMode = LockMode.NONE;

	/**
	 * Retrieve the overall lock mode in effect for this set of options.
	 * <p/>
	 * In certain contexts (hql and criteria), lock-modes can be defined in an
	 * even more granular {@link #setAliasSpecificLockMode(String, LockMode) per-alias} fashion
	 *
	 * @return The overall lock mode.
	 */
	public LockMode getLockMode() {
		return lockMode;
	}

	/**
	 * Set the overall {@link LockMode} to be used.  The default is
	 * {@link LockMode#NONE}
	 *
	 * @param lockMode The new overall lock mode to use.
	 *
	 * @return this (for method chaining).
	 */
	public LockOptions setLockMode(LockMode lockMode) {
		this.lockMode = lockMode;
		return this;
	}

	private Map aliasSpecificLockModes = new HashMap();

	/**
	 * Specify the {@link LockMode} to be used for a specific query alias.
	 *
	 * @param alias used to reference the LockMode.
	 * @param lockMode The lock mode to apply to the given alias
	 * @return this LockRequest instance for operation chaining.
	 *
	 * @see Query#setLockMode(String, LockMode)
	 * @see Criteria#setLockMode(LockMode)
	 * @see Criteria#setLockMode(String, LockMode)
	 */
	public LockOptions setAliasSpecificLockMode(String alias, LockMode lockMode) {
		aliasSpecificLockModes.put( alias, lockMode );
		return this;
	}

	/**
	 * Get the {@link LockMode} explicitly specified for the given alias via
	 * {@link #setAliasSpecificLockMode}
	 * <p/>
	 * Differs from {@link #getEffectiveLockMode} in that here we only return
	 * explicitly specified alias-specific lock modes.
	 *
	 * @param alias The alias for which to locate the explicit lock mode.
	 *
	 * @return The explicit lock mode for that alias.
	 */
	public LockMode getAliasSpecificLockMode(String alias) {
		return (LockMode) aliasSpecificLockModes.get( alias );
	}

	/**
	 * Determine the {@link LockMode} to apply to the given alias.  If no
	 * mode was explicitly {@link #setAliasSpecificLockMode set}, the
	 * {@link #getLockMode overall mode} is returned.  If the overall lock mode is
	 * <tt>null as well, {@link LockMode#NONE} is returned.
	 * <p/>
	 * Differs from {@link #getAliasSpecificLockMode} in that here we fallback to we only return
	 * the overall lock mode.
	 *
	 * @param alias The alias for which to locate the effective lock mode.
	 *
	 * @return The effective lock mode.
	 */
	public LockMode getEffectiveLockMode(String alias) {
		LockMode lockMode = getAliasSpecificLockMode( alias );
		if ( lockMode == null ) {
			lockMode = this.lockMode;
		}
		return lockMode == null ? LockMode.NONE : lockMode;
	}

	/**
	 * Get the number of aliases that have specific lock modes defined.
	 *
	 * @return the number of explicitly defined alias lock modes.
	 */
	public int getAliasLockCount() {
		return aliasSpecificLockModes.size();
	}

	/**
	 * Iterator for accessing Alias (key) and LockMode (value) as Map.Entry
	 *
	 * @return Iterator for accessing the Map.Entry's
	 */
	public Iterator getAliasLockIterator() {
		return aliasSpecificLockModes.entrySet().iterator();
	}

	/**
	 * Indicates that the database should not wait at all to acquire the pessimistic lock.
	 * @see #getTimeOut
	 */
	public static final int NO_WAIT = 0;
	/**
	 * Indicates that there is no timeout for the acquisition.
	 * @see #getTimeOut
	 */
	public static final int WAIT_FOREVER = -1;

	private int timeout = WAIT_FOREVER;

	/**
	 * Retrieve the current timeout setting.
	 * <p/>
	 * The timeout is the amount of time, in milliseconds, we should instruct the database
	 * to wait for any requested pessimistic lock acquisition.
	 * <p/>
	 * {@link #NO_WAIT} and {@link #WAIT_FOREVER} represent 2 "magic" values.
	 *
	 * @return timeout in milliseconds, or {@link #NO_WAIT} or {@link #WAIT_FOREVER}
	 */
	public int getTimeOut() {
		return timeout;
	}

	/**
	 * Set the timeout setting.
	 * <p/>
	 * See {@link #getTimeOut} for a discussion of meaning.
	 *
	 * @param timeout The new timeout setting.
	 *
	 * @return this (for method chaining).
	 *
	 * @see #getTimeOut
	 */
	public LockOptions setTimeOut(int timeout) {
		this.timeout = timeout;
		return this;
	}

	private boolean scope=false;

	/**
	 * Retrieve the current lock scope setting.
	 * <p/>
	 * "scope" is a JPA defined term.  It is basically a cascading of the lock to associations.
	 *
	 * @return true if locking will be extended to owned associations
	 */
	public boolean getScope() {
		return scope;
	}

	/**
	 * Set the cope.
	 *
	 * @param scope The new scope setting
	 *
	 * @return this (for method chaining).
	 */
	public LockOptions setScope(boolean scope) {
		this.scope = scope;
		return this;
	}

	/**
	 * Shallow copy From to Dest
	 *
	 * @param from is copied from
	 * @param dest is copied to
	 * @return dest
	 */
	public static LockOptions copy(LockOptions from, LockOptions dest) {
		dest.setLockMode(from.getLockMode());
		dest.setScope(from.getScope());
		dest.setTimeOut(from.getTimeOut());
		dest.aliasSpecificLockModes = new HashMap(from.aliasSpecificLockModes );
		return dest;
	}
}

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